Ultrapure water (UPW) is desirable for a variety of industrial processes, particularly pharmaceutical and semiconductor manufacturing. The semiconductor industry uses UPW as a universal solvent in virtually every step of a production process. Typical acceptable conductivity levels for UPW used in semiconductor industries are about 0.05 micro-siemens per centimeter (μ/cm) and typical acceptable total organic content (TOC) levels are about 1 ppb carbon. Chemical pharmaceutical industries use UPW in the production of drugs and reagents that require high degrees of purity. Typical acceptable conductivity levels for UPW used in pharmaceutical industries can be as high as 1.3 μS/cm at 25° C., and typical acceptable TOC levels can be up to 500 ppb carbon.
Ultra low levels of any ionic and non-ionic impurities (or the absence of impurities) therefore are desirable characteristics of UPW. Even small amounts of contaminants or electrolytes can adversely impact the efficacy or yields of the desired products. As semiconductor features decrease in size, smaller amounts of impurities, and certain types of impurities, become less tolerable.
For these reasons, determination of the nature of organic contaminants present in an UPW stream would be desirable and could lead to identification of the contaminant source, as well as remediation of the contaminants, which would be an invaluable cost and time saving tool.
Conventional TOC analyzers measure the amount of CO2 produced when organic carbon-containing molecules are oxidized and/or when inorganic carbon-containing molecules are acidified. TOC analyzers are, therefore, unable to identify the organic molecules in UPW.